A gas fitter wept today as he was jailed for the manslaughter of a millionaire's daughter who died from carbon monoxide poisoning following his botched installation of a boiler.
Andrew Hartley, 37, fitted the new boiler into Zoe Anderson's Bath home less than two weeks before she was overcome by gas fumes.
He was handed a three-year prison sentence after being told it was "simply the price he must pay".
Judge Neil Ford QC said there were "absolutely no malicious or hostile intentions in this case" but the loss to Miss Anderson's family was "profound".
A jury at Bristol Crown Court found Hartley guilty of manslaughter by gross negligence by a majority of 10 to two following a two-week trial last month.
Hartley, of Bath New Road, Radstock, Somerset, had already admitted a charge of breaching gas safety regulations under the Health and Safety at Work Act 1974 by failing to secure the boiler flue pipe with screws.
The family man appeared in court today dressed in a purple shirt and tie and was supported by his wife and two friends.
As the judge read out the gas fitter's sentence Hartley wiped tears from his eyes and his face was visibly reddened.
Judge Ford said: "On the 16th December you installed a new gas boiler at Sion Hill, a property owned by Chris Anderson and used from time to time by his daughter Zoe Anderson.
"On 28th December Zoe was overcome by carbon monoxide in the shower room and tragically died.
"Zoe was a young and talented woman with a fruitful life ahead of her.
"When you left the site you believed the flue was correctly fitted, but the flue was not connected to the turret elbow.
"The quality of work fell below your normal high standards.
"You knew the potential dangers of a carbon monoxide leak and leaving the flue unconnected created a clearly foreseeable risk to life and, as the jury found, amounted to criminal negligence.
"You were qualified, your record of work in the field was long and good. You are a wholly respectable man.
"Your sense of guilt can properly be characterised as overwhelming.
"There is no self pity in your approach to the tragedy, you are accurately aware of the suffering that you have inflicted on others and that the suffering of the Anderson family is the greatest of all.
"There is no prospect at all of you committing further offences, this is simply the price that you must pay for an isolated but serious criminal offence."
Judge Ford sentenced Hartley to three years in prison for manslaughter by gross negligence and one year, to run concurrently, for breaching gas safety regulations.
Hartley's wife sobbed from the public gallery as he was taken away to start his prison sentence.
During the trial the court heard that Miss Anderson, 24, the daughter of magazine tycoon Chris Anderson, was found dead by her boyfriend in the shower room of her father's home in Sion Hill - one of Bath's most exclusive streets - on December 29 2010.
At first it was thought the neuroscience graduate had slipped and banged her head, but later it was found she had collapsed from carbon monoxide poisoning.
The prosecution said Hartley did a "rushed" and "botch" job, failing to secure the flue pipe correctly.
Miss Anderson died within just 30 minutes of being exposed to the carbon monoxide after fumes leaked from the flue pipe connected to the boiler in the garage of the Victorian townhouse.
Hartley - who has been in the gas and plumbing industry for 20 years and had an unblemished career - was said by colleagues, acquaintances and friends to be reliable, professional and trustworthy.
Michael Fitton QC, defending, said today: "This is not a man who has lied to the police. This is not a man who has sought to escape what he did.
"He came to this court a man of good character, he came to this court respected as an employee and an employer.
"He stands here a family man and a businessman, whose family will suffer greatly in his absence.
"Your Lord has read powerful testimonies of my client as a friend, as a father, as a husband and as a good man.
"He stands here today knowing he will go to prison."
Hartley had previously told the jurors he admitted a charge of contravening gas safety regulations, which reflected his failure to secure the flue pipe with screws.
However, he denied he was grossly negligent and said he felt "awful" about not carrying out the installation properly.
"I didn't complete it the way I should have done because I didn't put the screws in," Hartley said.
He added that when he left Mr Anderson's home the Worcester boiler was working properly and he had fully tested it.
Miss Anderson's family were not in court today, but speaking following the verdict last month, her mother Lucy Evans, said her family had "felt an intense pain and bewilderment" following her death.
She added that she had found forgiving Hartley "hard work", but said her family were now hoping to now rebuild their lives.
Following her death Mr Anderson, the founder of the Future Publishing stable of magazines who now lives in America, described his daughter as "beautiful" and "larger-than-life".
A tribute page set up on Facebook described the last month of Miss Anderson's life as "one of the happiest months of her life" as she prepared for an internship in New York.
The page described Zoe as "living big. She touched the lives of everyone she met with her laughter, curiosity and generosity".
Mr Anderson started Future Publishing in 1994 with a £10,000 loan in his parents' garage in Somerton, Somerset.
He sold the company in 1994 for £52.7 million before buying it back four years later and selling it again in 2001.
He then headed for America where, based in New York, he is the owner of TED, which hosts talks by globally renowned thinkers.
Detective Inspector Neil Beament, who led the investigation, said: "This is a tragic, tragic case.
"Andrew Hartley is a professional tradesman with all the relevant qualifications.
"His substandard work has led to the death of Zoe Anderson, a young woman with a very bright future.
"The verdict and sentence reflects the severity of his failings and sends a clear message to all tradesmen in relation to the duty of care they owe all their customers.
"The case also highlights the dangers of carbon monoxide poisoning and I would urge all householders to consider the installation of appropriate devices.
"My thoughts are with Zoe's family at this very difficult time."
It is a legal requirement that anyone who carries out gas work must be registered on the Gas Safe Register.
To be registered, gas engineers have to provide proof of their technical expertise, including qualifications and certificates of competence, which they are re-tested on every five years.
In a statement the Health and Safety Executive said: "The householder in this case did the right thing- they employed a registered gas engineer who is legally allowed to work on gas appliances.
"However, the engineer failed to apply their competence and expertise, which has led to tragic consequences.
"It is vital that registered gas engineers always apply their knowledge and skills on every gas job they carry out and make sure gas work is left safe for people to use.
"If engineers cut corners they can expect to be held to account for their actions."